.\" ************************************************************************** .\" * _ _ ____ _ .\" * Project ___| | | | _ \| | .\" * / __| | | | |_) | | .\" * | (__| |_| | _ <| |___ .\" * \___|\___/|_| \_\_____| .\" * .\" * Copyright (C) Daniel Stenberg, , et al. .\" * .\" * This software is licensed as described in the file COPYING, which .\" * you should have received as part of this distribution. The terms .\" * are also available at https://curl.se/docs/copyright.html. .\" * .\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell .\" * copies of the Software, and permit persons to whom the Software is .\" * furnished to do so, under the terms of the COPYING file. .\" * .\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY .\" * KIND, either express or implied. .\" * .\" * SPDX-License-Identifier: curl .\" * .\" ************************************************************************** .\" .TH CURLOPT_OPENSOCKETDATA 3 "16 Jun 2014" libcurl libcurl .SH NAME CURLOPT_OPENSOCKETDATA \- pointer passed to open socket callback .SH SYNOPSIS .nf #include CURLcode curl_easy_setopt(CURL *handle, CURLOPT_OPENSOCKETDATA, void *pointer); .fi .SH DESCRIPTION Pass a \fIpointer\fP that is untouched by libcurl and passed as the first argument in the open socket callback set with \fICURLOPT_OPENSOCKETFUNCTION(3)\fP. .SH DEFAULT The default value of this parameter is NULL. .SH PROTOCOLS All .SH EXAMPLE .nf /* make libcurl use the already established socket 'sockfd' */ static curl_socket_t opensocket(void *clientp, curlsocktype purpose, struct curl_sockaddr *address) { curl_socket_t sockfd; sockfd = *(curl_socket_t *)clientp; /* the actual externally set socket is passed in via the OPENSOCKETDATA option */ return sockfd; } static int sockopt_callback(void *clientp, curl_socket_t curlfd, curlsocktype purpose) { /* This return code was added in libcurl 7.21.5 */ return CURL_SOCKOPT_ALREADY_CONNECTED; } curl = curl_easy_init(); if(curl) { /* libcurl thinks that you connect to the host * and port that you specify in the URL option. */ curl_easy_setopt(curl, CURLOPT_URL, "http://99.99.99.99:9999"); /* call this function to get a socket */ curl_easy_setopt(curl, CURLOPT_OPENSOCKETFUNCTION, opensocket); curl_easy_setopt(curl, CURLOPT_OPENSOCKETDATA, &sockfd); /* call this function to set options for the socket */ curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, sockopt_callback); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } .fi .SH AVAILABILITY Added in 7.17.1 .SH RETURN VALUE Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. .SH "SEE ALSO" .BR CURLOPT_CLOSESOCKETFUNCTION (3), .BR CURLOPT_OPENSOCKETFUNCTION (3), .BR CURLOPT_SOCKOPTFUNCTION (3)